Cloning and characterization of a periplasmic nuclease of Vibrio vulnificus and its role in preventing uptake of foreign DNA.

ABSTRACT: We have cloned a nuclease gene, vvn, from Vibrio vulnificus, an estuarine bacterium that causes wound infections and septicemia in humans and eels. The gene contained a 696-bp open reading frame encoding 232 amino acids (aa), including a signal sequence of 18 aa. The deduced amino acid sequence of the mature nuclease predicted a molecular mass of 25 kDa, which was confirmed by vital stain, and a pI of 8.6. Vvn was produced in the periplasm of either V. vulnificus or recombinant Escherichia coli strains and was active in the oxidized (but not the reduced) form. This nuclease was able to digest DNA and RNA, with differential thermostability in DNase and RNase activities. Expression of Vvn in E. coli DH5alpha reduced the frequencies of transformation with the divalent ion-treated cells and el

SUBMITTER: Wu SI 

PROVIDER: S-EPMC92521 | biostudies-literature | 2001 Jan

REPOSITORIES: biostudies-literature